Guest Column: Exploring rain garden plants

StoryImage( ‘/Images/Story//Auto-img-117943244711355.jpg’, ‘Photo courtesy of‘, ‘Rain gardens are shallow depressions, planted with different types of flowers, grasses or shrubs, that collect storm water and allow it to soak into the ground. They can be located in various places on a property to treat different sources of storm water (description courtesy of‘);

Last month, I described my ditch rain garden. So this month, I will give you a list of some plants that do well in and around rain gardens. Note that some of the wetland plants do better in calcareous soils. This means they like limestone. Since my garden does not sit on a limestone outcrop, I dug large holes and mixed in crushed limestone rock and gravel with the regular soil for those plants.

One of the things I’ve learned about rain garden plants is that there are not many short ones, so be prepared to have plants that are 3 to 6 feet tall. Of course, most of the plants listed here are available in our plant sale.

Soggy bottom plants

Asclepias incarnate, Red Milkweed—This is a must-have plant. It grows 3 to 4 feet tall and 2 feet wide. It blooms in late July to August with very showy clusters of pinkish-red flowers. This is a butterfly magnet and a vital food source for monarch butterflies and their caterpillars.

Carex bebbii, Bebb’s Sedge—This well-behaved clumping sedge looks like a coarse grass with arching leaves. Its spikes reach up to 30 inches high, and the small seed heads turn brown in early summer. This plant prefers calcareous soil.

Chelone glabra, White Turtlehead—Grows 2 to 4 feet tall and about 2 feet wide. The flowers are borne on spikes and resemble turtleheads. They bloom in late summer and brighten up the garden. Plant in groups of three with cardinal flower for a spectacular show. It is fun to watch the bumblebees crawl into the flower to collect pollen.

Eupatorium maculatum, Joe Pye Weed—Sometimes called Spotted Joe Pye Weed because the stems have purplish spots. Blooms in July to August, and draws butterflies and insects. The rather flat-headed clusters of pinkish flowers are borne on stems that reach 4 to 6 feet high, and the plant grows 2 to 3 feet wide.

Lobelia cardinalis, Cardinal Flower—Who does not love the brilliant scarlet flowers that appear in July to August? Hummingbirds and butterflies are drawn to this flower. Grows 2 to 3 feet high and 1 foot wide. Will grow in wet or moist soils. Note, though, this is a short-lived plant and, to ensure continuing plants, the seeds need the bare soil to grow new plants.

Lythrum alatum, Winged Loosestrife—This is one of the safe loosestrifes we can plant. Growing to 1 to 2 feet high and up to 2 feet wide, blooming in June to early August. The flowering stalks are covered with 1/2-inch lavender or purple flowers that are attractive to many insects, including many species of bees. The plant does tend to flop over, but planting these in groupings will help.

Scirpus cyperinus, Wool Grass—Not really a grass but closer to bulrushes. Grows 3 to 5 feet high in boggy or wet soil. It blooms in late summer into the fall. The seed heads turn a deep reddish brown and wooly. I have not grown this in the past, but will this year. It forms colonies, but I have been told it is not aggressive.

Verbena hastata, Blue Vervain—This showed up last year as a volunteer, and I was happy to see it. Grows to 5 feet tall and about 2 feet wide. Erect spikes are densely covered with reddish blue or violet flowers and bloom for a long time in mid- to late-summer. This is a biennial that will reseed itself on open, rich soil. Draws a variety of insects that collect nectar and pollen.

Aster novae-angliae, New England Aster—Nothing gets more of my neighbors to stop and admire the fall blooms than this wonderful aster. It grows 4 to 5 feet tall and 3 feet wide. It grows in normal to moist soils. It does tend to spread its branches out, almost flopping over, so it is best planted with tall plants to support it. It does reseed itself readily. Despite this, it is a great plant to have.

Liatris pycnostachya, Prairie Blazing Star—I wish I could grow more of these. The only problem is the voles eventually eat the corms, so lately I have been putting the corms in hardware cloth cages and then planting them. I see already that this has kept voles from getting to them. Stunning purple stalks of blooms appear in July to August, and blooms for about two weeks. The butterflies and insects love these, which grow to about 3 feet tall. It grows in wet to moist soil. Another blazing star that likes wetter soils is Liatris spicata, Marsh Blazing Star.

Solidago riddellii, Riddell’s Goldenrod—Grows 2 to 3 feet high and 2 feet wide and prefers calcareous soil. Blooms with showy clusters of golden yellow flowers in late summer to fall. Goldenrods are an important food source for migrating monarch butterflies.

If you want to take a look at my rain garden, just give me a call at 815-874-3468. A number of Web sites are available that can give you information about natives. One that I frequent is

Tim Lewis is immediate past president and national director of Wild Ones.

from the May 16-22, 2007, issue

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